Control device for use in a vehicle

ABSTRACT

The invention relates to a control device for use in a vehicle having a climate-control system. Means are provided for switching the ventilation to recirculated air operation. A first sensor for measuring the tendency of the window to become misted is arranged behind the recirculated air flap at the side facing the inner space of the vehicle.

The present invention-relates to a control device for use in a vehicle having a climate-control system, means being provided for switching the ventilation to recirculated air operation.

At an external temperature of below 5° C., it is only possible to switch to recirculated air operation briefly since the windows can otherwise become misted. Recirculated air is automatically switched to external air after 30 minutes at external temperatures of above 5° C., after 5 minutes at external temperatures of below 5° C., or after 5 minutes if economy operation is selected.

On the other hand, switching to recirculated air is automatically carried out if the content of carbon monoxide or nitrogen in the external air increases.

With the Climate Control Sensor marketed by the company Robert Bosch, excess consumption by climate-control systems in vehicles can be clearly reduced. The air conditioning system is primarily switched to recirculated air operation. It is not necessary to divert energy for the temperature control and dehumidification of the external air. However, since passengers exhale CO₂ when breathing, fresh external air must be introduced promptly into the interior of the vehicle. The sensor allows the climate-control system to be controlled in accordance with requirements. The length of time of the recirculated air operation can be extended.

When the recirculated air flap is closed, there is an increased tendency for the windows to become misted. This tendency can be reduced by the air being cooled or dried. Even with the recirculated air flap open, window misting may occur.

The object of the invention is to optimise the known control devices in such a manner that the tendency towards window misting is reduced in spite of recirculated air operation or economy operation.

This object is achieved by a control device for use in a vehicle having a climate-control system, there being provided means for switching the ventilation to recirculated air operation, in which there is arranged, behind the recirculated air flap at the side facing the inner space of the vehicle, a first sensor for measuring the tendency of the window to become misted.

The control device according to the invention can be arranged in a central or non-central manner. The invention can also be used in vehicles having a so-called automatic start-stop system, a system for utilising residual heat or a cold store.

A second sensor at the side facing away from the inner space of the vehicle in front of the recirculated air flap may be a noxious gas sensor for determining pollutants in the air supplied to the vehicle, whilst the first sensor may be a sensor for determining the tendency of the window to become misted (dew point sensor or air humidity sensor).

If there is a risk of the window becoming misted, the air can be cooled, dried, heated or ventilation can be carried out using the climate-control system. The ambient environment can be monitored.

Using the control device, it is possible to decide and control whether the recirculated air flap is closed or opened or whether other measures are necessary.

There may also be provision for an acoustic or optical signal to be transmitted when the window becomes misted with the recirculated air flap open. The ambient environment in the vehicle is monitored. Using technical means, instruments or tools of the vehicle, the tendency of the window to become misted with the recirculated air flap open can be prevented. These may be: heating, cooling, ventilation, use of residual heat, flap position, window heating.

If the invention is used together with an automatic start-stop system, the battery power is monitored so that the engine remains on if the climate-control system or power is required in order to reduce the tendency of the window to become misted.

Depending on the vehicle situation, the requirement for electrical power can be kept as low as necessary.

In summary, the invention involves controlling the behaviour of the recirculated air flap using a control device together with at least one sensor. The energy requirement is optimised. The control device decides how vehicle technical means, instruments or tools or the recirculated air flap should be used.

A preferred embodiment of the invention is illustrated in the drawing and is explained in greater detail with reference to the FIGURE, in which:

The FIGURE is a schematic illustration of a control device in accordance with the teaching of the invention.

From the FIGURE it can be seen that two sensors 2, 3 are arranged in an air supply channel 1 of a climate-control system of a vehicle. A sensor 2, 3 is arranged in front of and behind a recirculated air flap 4, respectively. This means that one sensor 3 is positioned at the side facing the inner space of the vehicle and the other sensor 2 is positioned at the side facing away from the inner space of the vehicle. The one sensor 2 is provided for measuring noxious gas which can potentially enter the inner space, whilst the other sensor 3 is constructed for measuring the tendency of the window panes to become misted. If the climate-control system is now operated in recirculated air operation, using the control device 5 which is connected to the sensors 2, 3, the recirculated air flap 4 can be controlled so as to move into the open or closed state. If noxious gas enters the vehicle inner space, this is detected via the first sensor 2. The recirculated air flap 4 is closed. Using the second sensor 3, the tendency of the window in the vehicle inner space to become misted can be determined. If the tendency is too high, the air is cooled or dried. The air flow is activated by means of a ventilator 6. The monitoring of the ambient atmosphere is completed by the use of a CO₂ sensor 7 and an O₂ sensor 8. 

1. Control device for use in a vehicle having a climate-control system and apparatus for switching ventilation to recirculated air operation, said device comprising a first sensor disposed behind a recirculated air flap at a side facing an inner space of the vehicle for measuring a tendency of a window to become misted.
 2. Control device according to claim 1, wherein a second sensor is provided in front of a recirculated air flap at a side facing away from the inner space of the vehicle, the second sensor being a noxious gas sensor.
 3. Control device according to claim 1, wherein the first sensor is integrated in a ventilator module.
 4. Control device according to claim 1 wherein the control device is integrated in a ventilator control system.
 5. Control device according to claim 1 further comprising a device for using information relating to the atmosphere and the heating of the vehicle.
 6. Control device according to claim 1 further comprising a CO₂ sensor.
 7. Control device according to claim 1 further comprising an O₂ sensor. 